WO 2004/013704 A1 describes a digital printing machine for direct non-contact sheet-fed printing having a digital printing couple that is unformatted in the circumferential direction, and having a transport apparatus downstream from the digital printing couple, wherein the transport apparatus has grippers for holding sheets on its periphery, the transport apparatus preferably having a plurality of transport cylinders and/or transport belts and/or impression cylinders.
EP 2 540 513 A1 describes a machine arrangement for the sequential processing of a plurality of sheet-type substrates, each having a front side and a back side, said machine arrangement comprising a first printing cylinder and a second printing cylinder, wherein at least one first non-impact printing unit, which prints the front side of the substrate in question, and a dryer, which dries the front side of the substrate in question that has been printed by the first non-impact printing unit, are arranged downstream from the first non-impact printing unit in the direction of rotation of the first printing cylinder, each on the periphery of the first printing cylinder, wherein at least one second non-impact printing unit, which prints the back side of the substrate in question, and a dryer, which dries the back side of the substrate in question that has been printed by the second non-impact printing unit, are arranged downstream from the second non-impact printing unit in the direction of rotation of the second printing cylinder, each on the periphery of the second printing cylinder, wherein the first printing cylinder and the second printing cylinder are arranged such that they form a common roller nip, wherein in this common roller nip, the first printing cylinder transfers the substrate in question, which has been printed on the front side and dried, directly to the second printing cylinder.
DE 103 12 870 A1 describes a digital printing machine for sheet-fed printing, having a digital printing couple that is format-free in the circumferential direction, an intermediate cylinder downstream from the digital printing couple, coated at least partially with an elastic material, and an impression cylinder downstream from the intermediate cylinder, wherein the impression cylinder has sheet-retaining grippers and the intermediate cylinder has recesses on its periphery for accommodating the grippers.
DE 101 56 800 B4 discloses a printing couple comprising a transport device embodied as rotational for transporting a printing stock sheet, which is embodied with a retaining device for retaining the printing stock sheet, and comprises an NIP (non-impact printing) print head aligned with the transport device for printing the printing stock sheet, wherein the retaining device is mounted to be periodically displaceable into the interior of the transport device.
DE 10 2015 211 440 B3 which was published subsequently discloses a sheet transport drum of a sheet processing machine having at least two sheet supporting surfaces with suction openings, wherein each sheet supporting surface is formed from a first and a second comb segment having segment prongs, wherein suction grooves are provided in the segment prongs and an undercut suction groove is provided in the sheet supporting surface of a respective second comb segment, and also having a rotary valve for cycled exposure to suction air, wherein a plurality of vacuum sources is provided, and each undercut suction groove is associated with a vacuum source via the rotary valve.
U.S. Pat. No. 6,363,234 B2 discloses a digital printing machine having a quadruple-sized printing cylinder.
U.S. Pat. No. 7,909,454 B2 discloses a digital printing machine having a printing cylinder on whose circumferential surface four printing sheets, each held by a retaining means, can be arranged in the circumferential direction, wherein the printing sheets are transferred from a single-sized transfer cylinder to the printing cylinder.
DE 10 2013 211 250 A1 discloses a printing machine having a plurality of printing couples that jointly print a printing stock, wherein at least two of these printing couples are arranged one behind the other in a row along a transport path provided for the printing stock, wherein at least one of these printing couples arranged in a row is embodied as an inkjet system, wherein the inkjet system in question is embodied such that this inkjet system prints varying or at least variable information on a target surface provided on the printing stock in an ongoing printing process, wherein at least one mark applied to the printing stock is present, wherein a detection device for detecting the at least one mark applied to the printing stock is provided, wherein an adjusting device that adjusts the position of the inkjet system in question at least transversely to the transport path provided for the printing stock is provided between the inkjet system in question and one of the printing couples arranged in a row for this inkjet system, wherein the current position of the inkjet system in question is or at least can be adjusted by positioning the inkjet system in question by means of the adjusting device on the basis of the at least one mark detected by the detection device in the ongoing printing process, relative to the position of the target surface that is provided for printing the varying or at least variable information in the ongoing printing process.
DE 10 2012 218 840 A1 describes a method for transferring a transfer film that is releasable from an imaging transfer layer to a printing sheet provided with an adhesive coating by means of a coating unit, wherein the coating unit comprises an impression cylinder and a pressing roller that form a common transfer nip, by means of which the transfer film can be guided from a film supply roll, touching the pressing roller, such that it comes to rest with the transfer layer on the printed sheet guided on the impression cylinder, and is guided under pressure, together with the printed sheet, through the transfer nip for transferring the coating, a) wherein in the application unit, adhesive is applied in the form of the image to the printed sheet, b) wherein in the transfer nip, a subject of the transfer layer is transferred with pressing from the transfer film to the printed sheet provided with an adhesive image, c) wherein a protective layer is applied at least to the transfer layer applied to the printed sheet in this way, d) wherein, after application of the protective layer, the protective layer is dried on the printed sheet, and e) wherein after drying of the protective layer, the printed sheet is overprinted with images over all or part of its extension, including the transfer layer and the protective layer.
DE 10 2014 010 904 B3 describes an apparatus for two-sided printing of sheet-type printing stock, wherein the printing stock is guided around more than 360° on an impression cylinder, wherein the active region of an ink application unit, which has already printed the front side of the printing stock on an impression cylinder upstream, is re-entered by the printing stock, this time with its back side facing the ink application unit, wherein the ink application unit can preferably be pivoted between two impression cylinders disposed downstream from one another, and wherein the pivotable ink application unit is an inkjet print head, for example.
DE 10 2009 000 518 A1 describes a sheet-fed printing machine having a feed unit for loading printing sheets to be printed into the sheet-fed printing machine, and having at least one printing couple and/or coating unit for printing the printing sheets with a static print image that is identical for all printing sheets, and having a delivery unit for discharging printed sheets from the sheet-fed printing machine, and having at least one printing forme-free printing unit integrated into the sheet-fed printing machine for printing the printing sheet with a dynamic, variable print image in particular, wherein the/each printing forme-free printing unit is integrated into the sheet-fed printing machine, where it can be controlled as a function of the process parameters or operating parameters or order parameters or quality parameters.